1. Field of the Invention
This invention relates to a portable electronic apparatus such as computers or word processors of the lap-top type, etc., and more particularly to a portable electronic apparatus having a flat panel display unit removably attached thereto.
2. Description of the Related Art
In recent years, portable computers or portable word processors of the lap-top type, etc. having a flat panel display unit have been popularized.
Among such lap-top portable electronic apparatus, there have appeared portable electronic devices constructed so that a low voltage driven LCD (Liquid Crystal Display) unit of a flat panel display unit is detachable or demountable from the body as shown in U.S. Pat. No. 4,749,364. In such display removably attached portable electronic devices, a connector on the body side for electrically connecting the body and the LCD unit is provided in a socket rotatable relative to the body. When the LCD unit is mechanically connected to the socket, it can be rotated, by the rotational operation of the socket, between the position where the keyboard is covered and the position where an operation is made by an operator. With these display detachable portable electronic devices, when the LCD unit is detached from the body and the body and a cathode ray tube (CRT) display are electrically connected, a display on the CRT can be conducted. Accordingly, when such display removably attached portable electronic apparatus is employed, operations of plural kinds of displays can be carried out with a single body in a manner that the LCD unit is used when there is a need to frequently carry about the body, and that a CRT display is used when a user wished to look at the pictorial image by a color display.
Since the display removably attached portable electronic apparatus of the structure shown in U.S. Pat. No. 4,749,364 is such that the connector on the body side is provided within the rotatable socket, it has the following drawbacks. First, without the attached LCD display, it is unnecessary for the rotatable socket to remain in the body. Since the rotatable socket still remains within body after the LCD has been actually removed therefrom, the socket may be incompatible with another type of display such as a CRT and therefore prevent the user from attaching this different type of display. Secondly, since it is required that a signal cable for electrically connecting the connector and a central processing unit (CPU) provided in the body and /or a power supply cable for delivering a power from the body to the LCD unit are disposed within the rotary shaft between the socket and the body, producibility is poor at the time of assembling the apparatus. Thirdly, if a unit using a high power supply voltage of the order of 200 volts such as a plasma display is used as a flat panel display unit, such a high power supply voltage is delivered through the connector within the socket and there might occur a danger such that an operator receives an electric shock if his hands erroneously come into contact with the neighborhood of the socket. Fourthly, if a flat panel display unit of a high power supply voltage is used, such a high voltage is delivered to the connector, and this high voltage is instantaneously entered into the display unit or is cut off from the display unit at the time of attachment and/or detachment of the display unit, rendering a great electric shock to the body or the display.